Showing posts with label 7mhz. Show all posts
Showing posts with label 7mhz. Show all posts

9 Jun 2015

VK3YE homebrew 7MHz SSB transceiver

Steve G1KQH (font, or is it fount (?) of all knowledge) sent me this link of the homebrew 7MHz SSB transceiver by VK3YE:
New Homebrew 7MHz QRP rig from VK3YE

5 Jan 2014

40m WSPR - instant success to Australia

Keeping at 1W from the FT817 into the Par end-fed I got instantly spotted in Australia at over 17200km this early evening. WSPR really is amazing. Reports from VK now both on 40m and 20m with the low wire antenna. Lots of other spots followed. More spots from VK7BO followed. Nearest station was G4IKZ just 18km away.

First 40m WSPR results with 1W to my Par end-fed

26 Feb 2013

40m WSPR with 50mW - best DX spot 6505km

Reports received with 50mW on 40m
Overnight I've been WSPRing with 50mW output on 40m using the Par 10/20/40 end-fed antenna down the garden.  The FT817 set to 500mW directly feeds a Telonic 10dB rotary attenuator set to 10dB attenuation, so no chance of radiation from a coax cable. The antenna is only about 15m long and just 5m average height above the ground. Results (see above) have been very pleasing with best DX report from the USA - K9AN at 6505km.

31 Jan 2013

TXing with a ferrite rod antenna on 7MHz

Just for fun this morning I tried WSPRing on 7MHz using JUST a ferrite rod wound coil and a 365pF tuning capacitor as a tiny loop antenna sitting on the desk. All other antennas and grounds were disconnected fully. I used one of the low tap positions to find a 1:1 SWR position and put the FT817 on 2.5W (3 blobs). The rod did not get warm. The wire used is around 0.5mm enamelled copper with around 60 turns, tapped at every few turns at the cold end.

The ERP was very small, although I have not yet measured it. To my total amazement, I got an immediate -24dB S/N WSPR report from OZ7IT in Denmark at 853km. Just proves how incredible WSPR is and what a powerful tool it is for simple experiments like this.

Ferrite rod TX antenna on 7MHz WSPR - it worked!